Drying oven



`C. G. PREIS DRYING OVEN I July 6,1926.

3 Sheets-Sheet 2 Filed Jan. 6. 1923 July 6 1926.

` C. G. PREIS DRYING OVEN Filed Jan.l 6. 19,23

3 Sheets-Sheet 3 zj Wam Patented July 6, 1926.

UNITED i lSTATI-:1S

CARL G. PREIS, OF LYNBROK,-NEW YORK, ASSIGNOR T0 AMERICAN CAN COMPANY,

, 1,591,683 PATENT OFFICE.

OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

DRYING OVEN.

Application led January 6, 1923. Serial No. 611,008.

This invention relates to drying ovens, particularly of the character which are used for drying or baking lithographed or lacquered sheets of metal.

An important object of the invention is the provlsion of a drying oven yfor this purpose in which the heated air is caused to circulate in a manner producing maxi-v mum .drying action in a limited space, thus reduclng the floor space required for the installation of an apparatus of this character.

The invention has for another object the` provision of means for proportionately controllin the admission and vescape of air from t e oven which will result in an approximately balanced air pressure at the ends of the'enclosed passageway through which the sheets are moved as they are being dried.-

A further object is'the provision of an automatic feed for delivering the sheets to a conveyer by which they are moved through the drying oven, in combination with a heating chamber of the foregoing. type which accomplishes an effective dry-l vention will be apparent as it is better unyderstood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings,

Figure 1 is a side elevation, somewhat in outline, of a drying ven and associated apparatus in which my invention is embodied Fig. 2 is an enlarged partial section, taken longitudinally through the oven;

Fig. 3 is an enlar ed transverse View, looking toward the rig t in Fig. 1; and

Fi 4 is a sectional detail, taken through the amper construction by which the admission and escape of air is proportionatel controlled.

T e apparatus illustrated in the drawings comprises a supporting frame 21, upon which is mounted a casing 22, which, in the present instance, is of arched formation and comprises an outer asbestoscement wall 23 and a .series of blocks 24, which may be of magnesia, or other heat insulating material, and are supported from within by a metal sheet 25. This casing, with a base 26, provides an enclosed heating chamber through which a conveyer 27 is adapted to move carrying lithographed Sheets 28, or the like, which are-to be dried.

Said conveyer comprises links 29 to each of which are secured prongs 31, `these being separately mounted, in the present instance, on a transverse :od 32. an endless chain which is directed around sprockets 33 and 34 at one end and sprockets `35 and 36 at the opposite end, said chain being driven from a suitable source of power which-is connected to rotate one of said sprockets. An angle iron track 37 is provided upon supports 38 extending up from the base 26 and upon hangers 39 depen-ding from the frame 2l.

By means of the sprockets heretofore described, said chain is directed along the tracks 37 and the conveyer, carrying the lithographed sheets in spaced relationship and slightly inclined position, as shown in Fig. 2, is moved through the drying chamber.- It' willbe noted, in this connection, that the prongs of the conveyer are ymounted in such manner as to extend atan angle with respect to the vertical when moving through the oven and this causes the individual sheets to rest against the particular prongs by which they are carried and prevents the coated surfaces from coming into contact with adjacent prongs or sheets. p One pair of the prongs 31 isconnected rPhe links 29 form with each of the links 29 so that when the no y and is lifted and carried by said prong as it turns into the oven. In this manner, an automatic feed is provided which eliminates the necessity of manual delivery of the sheets to the dryer conveyer and which positions them in the conveyer without the likelihood of their being jarred, or having the edgs or surfaces thereof in any way damage For the purpose of tightening the conveyer chain 27, I provide a device, illustrated at the leftI in Fig. 1. A slide 43 carries the sprockets 35 and 36 and is held under the tension of a spring 44 mounted on a rod 45 between said slide and a block 46. The block 46 may be adjusted by a screw operable by a hand wheel 47 and it will be manifest that, upon movement of the sprockets 35 and 36 away from the sprockets 33 and 34, at the opposite end of the conveyer, the chain will be tightened, taking up any slackness which may result from the stretching of the chain in service.

The oven wall at this end is curved downwardly, as indicated at 48, and cut away angularly, as shown at 49, to provide an opening through which the conveyer and sheets may pass without leaving the end of the heating chamber entirely open. It will be manifest that this construction will tend to prevent escape of the heat within the chamber so that a relatively uniform temperature may be maintained and 'the sheets immediately subjected to this temperature upon entrance into the oven.

For the purpose of heating the air which is circulated through the oven in a manner to be hereinafter described, I provide any suitable heating means, such, for example, as a burner 51. Said burner is served with gas supplied through supply pipes 52, the feed being suitably regulated by valves generally indicated at 53. A thermostat is positioned on the interior of the oven at 50 and is connected to operate the regulating valves in such manner as to control the amount of gas fed to the burner, thus insuring substantially uniform temperature within the oven. A by-pass 60 is provided for independent control of the gas supply. Said burner 51 is disposed in a housing 54, through which the air is directed by a fan 55 drivenfby a motor 56 and a belt 57, or in any other 'approved manner. A housing 58 for said fan 55 is mounted upon a frame 59 which eX- tends up at opposite sides of the oven and across the top, providing also a support for themotor 56 and a portion of the housing 54.

A fresh air intake pipe 61 is provided above and slightly to one side of the fan and is mounted in an extension 62 of the oven wall 22. A passageway 63 leads fiom the intake pipe into the fan housing and the air delivered through said intake pipe and passageway is directed past the burner 51 and into the heating chamber at the top.

An inner shell, or wall part, 64 is arranged within the oven and spaced from the inner wall by means of supporting channel irons 65 and spacing members 66.

The air thus introduced is circulated through the oven in a novel manner, which will now be described and which may be ,most clearly understood by reference to Fig.

3. The incoming air is directed downwardly in the passageway 67 formed by the inner shell, or casing, 64, as indicated by the arrows in said Fig. 3. It is then introduced at the side through an opening 68, the eX- tentl of which may be regulated by a slide 69 and is directed\upwaidly by a delector 71 disposed across the passageway 67 and extending upwardly withiii the opening 68. The circulation in the chamber within the wall 64 follows generally the direction of the arrows in Fig. 3, from which it will be observed that the course is upwardly at one side and down across the sheets 28 and back therebeneath to the opening 68 beneath the delector 71. From this opening, the course followed is across beneath the lower wall 72 of the easing 64, upwardly through the passageway 67 at the right of Fig. 3, through the pipe 61 and through the lateral passage G3, this outward flow being caused by tie suction fan. The lower end of the pipe 61, it will be observed, extends across the passageway 67 and serves to direct the upwardly moving air out of the casing. The air which has thus been circulated through the oven is again directed into the fan housing 58 and in part directed back around the same course, it being understood that the circulation is largely continuous and that the air is kept heated by the burner 51. With the foregoing construction and method of circulating the air, the sheets 28 are subjected to intensified drying heat produced by radiation from the wall 64 and bottom 72, and also by direct circulation of the heated air between said sheets.

A discharge pipe 73 is provided between the fan 55 and the burner 51 and permits the escape of foul air and gases in amount to be hereinafter explained in detail. Said pipe 73 extends through a vent in the roof aiidis designed to carry oli' all discharge from the oven and to prevent the escape of any foul air or gases into the room.

I provide a damper control for regulating both the intake and discharge openings in the pipes 61 and 7 3, respectively, the damper mechanism being illustrated in detail in Fig. 4. Arranged upon the pipe 61 is a damper boX 74, in which a damper 75 is positioned and adapted to slide through an opening iii the pipe. A similar damper box 76 is arranged upon tlie pipe 73 and contains a damper 77, which is connected by an adjustl Ill) able connection 78 with the damper 75. The areas of the pipes 61 and 73 are such yas to cause proportional variation between the inlet and outlet openings by the movement of the unitary damper mechanism. It will thus be seen that when the intake opening 79 admits a certain amount of air, the outlet opening 81 will allow the escape of an amount which is in predetermined proportion to that admitted and that movement of the damper mechanism toward the left in Fig. 4 will cause an increasing difference between the amount of air enterin and escaping. When moved in the opposlte direction, this mechanism, which may be called a comfpound damper or valve, cuts down the out ow in predetermined ratio to the inflow, there being a progressively decreasing difference in the volume passing through lche two openings. In this manner, the air pressure at the ends of the oven is kept in approximately balanced condition, preventing theescape of foul air, or the intake of cold air, with the result that 'the temperature within the oven may be maintained substantially uniform throughout.

As the sheets emerge from the Ydrying chamber through an opening 82V at the right of the oven, as shown in Figs. 1 and 2 they are cooled by means vof a blower 83 which draws cool air past the sheets and out through an exhaust pipe 84:.` The blower may be driven by means of a shaft 85 and a driving belt 86 from any suitable source ot' power. B means of this device, the sheets are coo ed very rapidly so that they are capable of being handled by attendants lwithout the necessity of their being carried a very great distance beyond the heating chamber, there being a consequent reduction in the floor space required for the apparatus.

Sheets are delivered from between the prongs of the conveyer 27 ont'o a short delivery conveyery 87, from which they are removed and stacked upon a portable support 88, this being accomplished preferably by means of a stacker and flyer arm mounted in a frame 89, this arm and the operation thereof being more particularly illustrated in my co-pending application, Serial No. 611, 009, filed on Jan. 6, 1923.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts, without departing from the spirit and scope of the invention, or sacrificing all of the material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I` claim: v

1. A drying oven, comprising la casing providing a eatin chamber, a conveyer adapted to receive ithographed sheets, or

the like, in s aced relationship and to move them throng said chamber in substantially upright position, a heating wall spaced from said caslng and forming therewith an air passage extendin substantially around the outer part of sai chamber, and means for directing heated air through said passage and causing circulation thereof within said chamber immediately about the sheets on said conveyer.

2." A drying oven, comprising a casing providing a heatin chamber, a conveyer adapted to receive lit ographed sheets, or the like, in spaced relationship and to move them through said chamber in substantially upright position, a heating wall spaced from said caslng and forming therewlth an air passage extending substantially around the outer part of said chamber, and means for directing heated air downwardly in said passage at one side, into and through the space immediatelyl around said sheets and thence out and around substantially the remainder of said passageway and out of the casing.' l

` 3. A dryin oven, comprising a casing providing a eatin chamber, a conveyer adapted to receive y whereby t e latter are subjected to the heat radiated from said wall and resultant from the directcurrents of air.

4. A drying oven, comprising an outer casing, a shell disposed within said casing and spaced therefrom a conveyer adapted to ca lithographe sheets or the like through said shell, and means for directlng heated air through the passage between said casing and shell and through the space through which said sheets are passed. Y'

5. A drying oven, comprising a casing providing a heating chamber, an -endless chain conveyer for conveying l1thographed sheets, or the like, through said chamber to be dried, means for causing circulatlon ,of heated air within said chamber, and single damper means for proportionately regulating the supply of fresh air to and discharge of foul air from said chamber.

6. A dryin oven',y comprising a caslng providing a heating chamber, an endless chain conveyer for conveying artlcles to be dried through said chamber, means for supplying heated air in the chamber, means for proportionately regulating the supply of fresh air to and discharge of foul air from said chamber, and means for maintaining the circulation into and out of said chamber thographed sheets, or, .the like,'in spaced relationship and to move of the heated air which is not replaced by fresh air.

' 7. A drying oven, comprising a casinga shell disposed within said casing and spaced therefrom, means for causing circulation of heated air about the outside of and also into 'said shell, and a conveyer having articleholding means for moving articles to be dried through said shell.

8. A drying oven, comprising a casing, a shell disposed within said casing and spaced therefrom, means for causing clrculation of heated air about the outside and within said shell, a conveyor for moving lithogral'ihed sheets, or the like` through said shell. to be dried, sprockets at opposite ends of the casing about which the conveyer is adapted to bef directed, said conveyer comprising a `chain with successively arranged rongs s ecured to individual links thereo whereby said links open in fanlike manner as the chains move about said sprockets, and means for automatically feeding the sheets to be dried between the separated prongs as they are'moved about a sprocket.

9. A drying oven, comprising a casing, means for causing a substantially uniform and relatively high temperature in said casing, a. eonveycr moving through the casing, means for circulating heated air in direc- -tions crosswise of the casing and around the conveyer, means for automatically delivering sheets to be dried to said conveyer, and means for cooling the dried sheets as they emerge from the conveyer.

10. A drying oven, comprising an elongated casing, a conveyer adapted to convey lithographed sheets, or the like, through said casing to be dried, means for circulating air about said casing and maintaining the temperature thereof substantially uniform and relatively high, and means for cooling the sheets as they are delivered from said casing. l

11.- ]n an oven for drying lithographed sheets and the like, the combination of' an outery heat insulated casing, a metal shell disposed within and spaced from said easing, means for conveying sheets to be dried through said shell, and means for causing circulation of heated air around the exterior yof said shell and directly about the sheets and circulating heated air on the interior thereof immediately about said sheets.

13. A drying oven, comprising an elongated casing, a conveyer for moving lithographed sheets, or the like, through said casing, a housing positioned above said casing and communicating therewith, a burner in said housing, and Ineans for directing air through said housing to be heated and causing circulation of the heated air about said casing.

14. A drying oven, comprising an elongated casing, a conveyer for moving lithographed sheets, or the like, through said casing, a housing positioned above said casing and communicating therewith, a burner in said housing, means for directing air through said housing to be heated and causing circulation ot' the heated `air about said casing, and means for admitting and discharging air from said housing.

15. A drying oven, comprising an elongated casing, a conveyer for moving lithographed sheets, or the like, through said casing, a housing positioned above said casing and communicating therewith, a burner in said housing, means for directing air through said housing to be heated and causing circulation ot the heated air about said casing, and means for admitting and Vdischarging air from said housing in predetermined variable proportions.

16. A drying oven, comprising a casing providing a heating chamber, means for conveying lithographed sheets, or the like, through said chamber to be dried, means for causing circulation of heated air through said chamber, and means for causing recirculation of a portion of said air with a substantially continuous flow.

17. A drying oven comprising an elongated casing forming an oven chamber, an endless chain conveyer 'for moving lithographed sheets or the like through said chamber` a single burner at the upper part of said chamber, and means for directing the heated air through said chamber.

18. A drying oven comprising an elongated casing forming an oven chamber, an endless chain conveyer for moving litho- `graphed sheets or the like` through said chamber, a burner at the upper part of said chamber and means for directing the heated air downwardly in said chamber, said air thereafter rising naturally in said chamber and a portion of it being reheated by said burner and again directed downwardly in said chamber. 1

CARL G. PREIS. 

